Tysons has developed wildly in the recent past. In addition Tysons Corner shopping mall, many high-tech industries have settled in the Tysons / Dulles corridor. These include major developers and users of open source software, e.g., Red Hat. Commuters now use METRO trains, the elevated tracks of which are visible in this image.
The old W&OD RR is long gone; it's right-of-way now serves as the the W&OD Trail, a bike and walking path from Arlington to Purcellville, VA.